feat(clustering/rpc): support jsonrpc notification

[chronolaw]

Summary

KAG-5893

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

Fix #[issue number]

[chobits]

From the Json-RPC 2.0 spec, I think the reply MUST contain id field. So could we check whether there is a payload.id right after the line local payload = decompress_payload(data)

[chobits]

like

local payload = decompress_payload(data)

-- check id firstly
if not payload.id then
   return error_log("not found id")
end

if type(payload.id) ~= number then
   return error_log("invalid id: not a number")
end

-- From now on, we assure that payload.id exists and it is a number
...

[chronolaw]

No, the examles in json rpc spec:

--> {"jsonrpc": "2.0", "method": "update", "params": [1,2,3,4,5]}
--> {"jsonrpc": "2.0", "method": "foobar"}

[chobits]

diff with _M:call(node_id, method, ...), I think we could combine them into one

@@ -1,4 +1,4 @@
-function _M:notify(node_id, method, ...)
+function _M:call(node_id, method, ...)
   local cap = utils.parse_method_name(method)

   local res, err = self:_find_node_and_check_capability(node_id, cap)
@@ -30,8 +30,25 @@ function _M:notify(node_id, method, ...)
   assert(res == "concentrator")

   -- try concentrator
-  local fut = future.new(node_id, self.concentrator, method, params, true)
+  local fut = future.new(node_id, self.concentrator, method, params)
   assert(fut:start())

-  return true
+  local ok, err = fut:wait(5)
+
+  if err then
+    ngx_log(ngx_DEBUG, "[rpc] ", method, " failed, err: ", err)
+
+    return nil, err
+  end
+
+  if ok then
+    ngx_log(ngx_DEBUG, "[rpc] ", method, " succeeded")
+
+    return fut.result
+  end
+
+  ngx_log(ngx_DEBUG, "[rpc] ", method, " failed, err: ", fut.error.message)
+
+  return nil, fut.error.message
 end

[chronolaw]

We could do it later.

[chronolaw]

refactored.

[chronolaw]

We should add test cases for it later.

[team-gateway-bot]

Successfully created cherry-pick PR for master:

• https://github.com/kong/kong-ee/pull/11018